Azure VM Stop Start Automation - azure

Question

We have an Azure subscription and 100 VMs to serve as workstations, and due to cost reduction, I would like to set up an Azure VM automation to accomplish the following:
Check all 100 VMs for idle and no users connected state.
Automatically power off 50% of the idle VMs with no users connected on it and send email to admin
If the total used capacity/number of VM reach 90%, power on a certain number of VMs
Btw, all VMs are not in VMSS. Thanks.

Answer 1

We have an Azure subscription and 100 VMs to serve as workstations,
and due to cost reduction, I would like to set up an Azure VM
automation to accomplish the following:
Check all 100 VMs for idle and no users connected state.
Automatically power off 50% of the idle VMs with no users connected on it and send email to admin
If the total used capacity/number of VM reach 90%, power on a certain number of VMs
There are 2 ways you can accomplish this.
To check the CPU utilization percentage and send an alert with an email and shut down the VM’s via an action group. Create another alert to check VM’s CPU capacity reaching 90% and Power ON other Vm’s.
Refer -https://blog.e-zest.com/auto-stop-your-vm-based-on-cpu-utilization
To enable Log analytics workspace and get your VM’s syslog to check the uptime of the processes and events of the VM and then create an alert rule to send an email based on those logs and run an automation runbook or an action group to turn on/off the VM’s.
Refer -https://energizedanalytics.com/how-to-save-money-by-automatically-stopping-idle-virtual-machines-in-azure-2/
Approach 1)
I enabled Azure Monitoring for all the VM’s in my subscription like below which will log all Vm’s metrics, syslogs, events etc. :-
I created an alert with a scope selected to all the VM’s in my Subscription.
Created an alert to check the VM’s CPU utilization below 5 % to know it is idle and send an email notification like below :-
Create Azure Automation account to run the PowerShell script to Stop or Power off the VM when idle or CPU utilization is below 5%.
Click Next and Create.
Alert will be triggered like below and VM will be stopped.
Create a new alert to get Vm’s CPU utilization above 90% and run the automation to start the VM’s.
Approach 2)
Enable Log analytics for specific VM’s to get the Vm’s performance counters on Vm’s uptime.
Go to your Log Analytics Workspace > Agents Management > Data Collection Rule > Custom > Select Vm’s Uptime and create a rule to get all the Vm’s uptime like below :-
The logs will populate in the selected log analytics workspace> Create an Alert rule with Action group to stop the VM’s and start VM’s as above.
Create or select an existing Action Group and Create an Alert to start or stop the VM’s according to the CPU percentage.